Ben Affleck thinks Jen has a great ass but he prefers her beautiful mind!

Los Angeles - Ben Affleck thinks Jennifer Garner has a "great ass".

The Gone Girl actor admires the fact that his wife - with who he has children Violet, eight, Seraphina, five, and Samuel, two - chooses "thoughtful" movie roles rather than accepting light material where her looks are important.

He said: "I like that she picks smart, interesting movies to make, not goofy rom-coms where she shakes her ass and stuff.

"Don't get me wrong, she's got a great ass but I prefer that she's choosing to do more thoughtful films than that."

And the 42-year-old star feels "grateful" that his wife takes on the bulk of childcare in their household but is still able to find the time for her own career.

He added to Britain's Hello! magazine: "If a woman's at home she goes, 'Why aren't I out in the world working?' and if she's at work she's going, 'Why aren't I at home with the kids?' If she does half and half she doesn't feel she's properly serving either master.

"It's a very difficult choice that has to be made and Jen handles it frankly as well as anybody I know. I'm really grateful to her.

"She says, 'I'm going to have the primary responsibility for the kids, but I'm also going to find a way to do movies at the same time.' I like the way she does this."